Geographic Range

Hyaena brunnea is native to the Ethiopian biogeographic region. Its current distribution is limited mainly to southernmost Africa, including the Kalahari and Namib Deserts as well as the Skeleton Coast, which borders the southern Atlantic Ocean. Hyaena brunnea is not frequently found north of the Angola-Namibia border or south of the Orange River in South Africa. (Mills, 1982a; Skinner and Chimimba, 2005; Stuart and Stuart, 2001)

Physical Description

Brown hyenas are medium to large carnivores, averaging 40.7 kg in mass with a range of 34.2 to 72.6 kg. Body length averages 144 cm with a range of 130 to 160 cm. Owens and Owens (1996) found no significant evidence of sexual dimorphism between males and females. However, the average mass of males and females is sometimes listed separately at 47 kg and 42 kg respectively (Stuart and Stuart, 2001). Both sexes average 78.7 cm in height at the shoulder. (Mills, 1982a; Nowak, 2005; Owens and Owens, 1996; Skinner and Chimimba, 2005; Stuart and Stuart, 2001; Wiesel, 2008)

Reproduction

Brown hyenas typically mate during the African dry season from May to August, following a brief courtship that may last from 3 to 6 nights. They generally exhibit one of two complex mating systems. The first is a clan-based polygynous system, which only occurs when the clan’s alpha male is a non-related individual from another clan. Related males and females generally do not show sexual interest in one another, however males born into a clan have been observed to rise to the status of alpha male and reproduce with clan females on rare occasions. In this first scenario, the alpha male mates with all clan females that are sexually receptive at any given time. He aggressively defends the clan from male intruders using piloerection and biting when necessary. If a nomadic female ventures into the clan’s territory, he may also mate with her. The second mating system consists of the sexually receptive clan females mating primarily with one or more nomadic males that venture into the clan’s territory. This system is either polygynous or promiscuous, with females occasionally mating with as many as four different males. In this scenario, both male and female clan members tolerate the presence of nomadic males. Nomadic individuals likely locate clans by sense of smell, using territorial scent markings and latrine sights made by the clan. (Mills, 1982b; Mills, 1982a; Owens and Owens, 1996)

Brown hyena clans exhibit cooperative breeding. Mothers suckle the cubs of other females, and all clan members take part in bringing food back to the den for cubs that are too young to hunt. (Mills, 1982b; Mills, 1982a; Owens and Owens, 1996)

Female brown hyenas may have more than one estrus cycle per year (i.e., polyestrus). Cubs are born with their eyes closed after an average gestation of 97 days. Newborns weigh an average of 693.2 g and are similar in coloration to their parents, but with shorter fur. Litters range in size from 1 to 5 individuals per female (2.3 on average) with alpha females generally having a higher lifetime reproductive output than subordinates. Cubs are almost entirely dependent on their mother’s milk for the first 3 months of their lives, but they may also occasionally suckle from other clan females. Weaning takes place when the cubs are 3 to 12 months old. Once weaning begins, their diet is gradually supplemented by red meat brought back to the den by other clan members. Cubs spend most of their time within or very close to the den until they reach 15 months of age. From 15 to 30 months of age, individuals are referred to as subadults and are capable of foraging independently. Females become sexually mature by 24 months, and males become sexually mature by 40 months. Females may wait anywhere from 12 to 41 months between successive litters. (Mills, 1982b; Mills, 1982a; Owens and Owens, 1996; Skinner and Chimimba, 2005)

Breeding frequency ranges from 12 to 41 months, and in some cases is largely dependent on the presence of nomadic males.

Breeding season

Breeding primarily takes place during the African dry season (May to August), but may also be based on the spontaneous arrival of nomadic males.

Range number of offspring

1 to 5

Average number of offspring

2.3

Average gestation period

97 days

Range weaning age

3 to 14 months

Range time to independence

15 to 30 months

Average age at sexual or reproductive maturity (female)

24 months

Average age at sexual or reproductive maturity (male)

40 months

Brown hyena mothers usually give birth to their cubs in private satellite dens and then introduce the cubs to the clan’s communal den before they are 4 months old. Mothers nurse their cubs until they are at least 10 months old (in some cases up to 14 months), but it is common for other lactating females to help by allowing non-offspring to nurse as well. Young cubs sometimes indicate a desire to suckle by pushing on the mother’s mammary glands with their front paws, a behavior know as “milk treading”. A typical nursing bout lasts for 25 to 30 minutes, but is sometimes extended if begging persists. Cubs less than 4 months old are fed 2 to 3 times per night, while older, weaning cubs often suckle only once every few nights. During weaning and prior to independence, mothers remain somewhat partial to their own offspring, but all clan members (both male and female) bring back scavenged food for the cubs. Adults carry food back to the den in their mouths and do not regurgitate as in some mammals. Females spend short periods of time sleeping and socializing with cubs near the den between nightly hunts, but both males and females typically sleep further away from the den during the day. Although fathers bring food back to the den, they do so less frequently than females and no more often than other clan males. Aside from bringing back food, paternal care by the alpha male also includes protecting cubs from predators and intruders from other clans. Mothers and other adult females also share in this task. Most cubs become independent by 15 months of age, but may still rely on communal food at the den until they reach 30 months of age. (Owens and Owens, 1979; Owens and Owens, 1996)

Lifespan/Longevity

In the southern Kalahari Dessert, 86% of brown hyena cubs survived to at least 15 months of age. Hunting by farmers is a common cause of death for young adults and subadults who wander out of their territory. Mature adults typically have a low mortality rate, and their greatest threat is the presence of larger carnivores such as African lions. For individuals that reach old age (around 10 years), tooth wear is the limiting factor for survival, and most die as a result of inadequate nutrition. (Mills, 1982a; Skinner and Chimimba, 2005)

Behavior

Hyaena brunnea is nocturnal, which helps it avoid extreme heat by focusing most of its activity between the hours of 7:30pm to midnight and then again, after a short rest, from 2:30am to 6:00am. During the day, adults sleep under the cover of trees, bushes or rocks to avoid becoming overheated. Adults hunt alone, following previously used trails that they have scent-marked. Nightly outings cover an average distance of 32 km, but individuals sometimes travel as much as 54 km. While foraging, adults travel at 3.2 to 6.4 km/h on average, but they can run at speeds of 40 to 50 km/h when necessary. Food that is not immediately consumed or brought back to the cubs is sometimes buried under bushes or trees for future recovery. (Hulsman, et al., 2010; Mills, 1982b; Mills, 1982a; Mills, 1982c; Nowak, 2005; Owens and Owens, 1978; Owens and Owens, 1979; Owens and Owens, 1996; Skinner and Chimimba, 2005; Wiesel, 2008)

Brown hyenas live either nomadically or as members of a clan. Approximately one third of all males are nomads that have left their birth clans and are searching for another clan to join as the alpha male. Females are occasionally nomadic, but only when they do not have cubs to care for. Brown hyena clans are small, normally made up of 5 to 15 individuals. Clans typically consist of genetically related males and females, but alpha males are usually migrants from another clan. The social structure of the clan consists of both male and female linear dominance hierarchies that can be independent of age. The alpha male and alpha female share equal positions in the clan hierarchy, and unlike spotted hyenas, brown hyena females are not consistently dominant over males. Dominance is established through ritualized bites to the legs and neck, as well as muzzle wrestling. Dominant individuals exhibit behaviors such as snapping their teeth, chasing, and raking their hind feet in front of subordinates. Brown hyenas use piloerection on their back and neck (also known as the hackle) as an aggressive or defensive gesture. When the display is aggressive, the mouth is closed, ears are alert and tail is up. In a defensive posture, the mouth is wide open and the ears lay flat against the back of the head. When individuals encounter one another, subordinate individuals greet by crouching low to the ground in a stereotypical posture and lifting its tail to present the anal scent gland. They flatten their ears outward at a 90-degree angle, and the lips are pulled up into what is generally described as a grin. This behavior is sometimes accompanied by squealing by the subordinate. Cubs practice these behaviors with one another from an early age. (Hulsman, et al., 2010; Mills, 1982b; Mills, 1982a; Mills, 1982c; Nowak, 2005; Owens and Owens, 1978; Owens and Owens, 1979; Owens and Owens, 1996; Skinner and Chimimba, 2005; Wiesel, 2008)

Home Range

Nomadic individuals are not territorial and therefore do not defend specific home ranges. In contrast, clans defend home ranges averaging 300 square kilometers, with some growing to as large as 480 square kilometers. Home range size changes periodically as a result of environmental conditions, growing larger when food and climate conditions are favorable. This territory includes the communal den site, smaller satellite dens and most of the hunting grounds used by the clan. The boundaries of a clan's home range are regulated using scent markings. Within the clan's territory, some individuals (many times a new mother with cubs) spend short periods of time in smaller sub-territories that average around 40 square kilometers in size. (Mills, 1982a; Nowak, 2005; Owens and Owens, 1978)

Communication and Perception

Hyaena brunnea has a well-developed sense of smell, which plays an important role in con- and heterospecific communication. When individuals meet, a thorough scent examination of the neck, head, back and anal gland takes place. Scent markings throughout the territory play an important role in communicating valuable information from one clan member to another without direct physical interaction. The anal secretions of brown hyenas consist of two elements. The first is a black paste with an odor that fades relatively quickly and conveys the message to other clan members that an area has recently been searched for food, which helps reduce foraging time in areas devoid of resources. The second element is a whitish paste that can last up to 30 days. These secretions are used to express territorial boundaries to members of other clans. Members of both sexes generally leave these secretions by squatting and rubbing their anal gland over a stick or a stalk of grass. The black paste is always observed above the white paste on a marked object. Individuals of both sexes scent mark 2.6 times per km on average, but markings are left more frequently towards the boundaries of the territory. Defecation sites are also used to convey scent messages about what individuals have recently eaten, and are typically found near the den or around territorial boundaries. (Attenborough, et al., 2002; Gorman and Mills, 1984; Mills, 1982a; Skinner and Chimimba, 2005; Wiesel, 2008)

In addition to scent markings, brown hyenas communicate using two visual displays via piloerection of the long fur on their hackles. In an aggressive display, the tail is laid against the back, the ears are alert and the mouth is closed. Defensive displays are characterized by an open mouth and flattened ears. Cubs communicate their desire to suckle by pushing on the female’s mammary glands with alternating front paws. Cubs also groom one another and the adults as a way of bonding. Vocal communication is also an important part of social behavior in brown hyenas. Whines and squeals are used as a warning for approaching predators and as a sign of submission to dominant individuals. A relatively quiet call is used to order cubs into the den. Deep growls sometimes accompany a meeting between rivals from separate clans, and shrieks are used to announce the presence of other predators at a newly discovered carcass. (Attenborough, et al., 2002; Gorman and Mills, 1984; Mills, 1982a; Skinner and Chimimba, 2005; Wiesel, 2008)

Food Habits

Hyaena brunnea is a generalist and a highly opportunistic feeder. Individuals primarily scavenge for carrion, using their acute sense of smell to locate carcasses and their specialized teeth to crush bone. Brown hyenas do not typically hunt live prey, but when an opportunity arises, they do not hesitate to pursue small birds or mammals over short distances. Diets vary from inland Botswana populations to those in the Namib Desert and along the Skeleton Coast. The diet of inland populations is largely composed of carcass remains from the kills of other large carnivores, such as African lions, and leopards. Frequently consumed food items in this area include springbok, springhare, gemsbok and Burchell's zebra. Populations living closer to the Skeleton Coast in western Namibia primarily feed on black-backed jackals and South African fur seal pups that have wandered from their parents or drowned. In both regions, birds such as the crowned plovers and helmeted guineafowl also make up a significant portion of their diet. In addition to meat, brown hyenas consume a high volume of tsama melon (Citrullus vulgaris), hookeri melon (Cucumis hookeri) and gemsbok melon (Citrullus naudinianus) as supplements for fresh water during the dry season. This feature of their diet allows brown hyenas to live in more arid regions than their close relative, the spotted hyena. Excess food that cannot be consumed in a single feeding is sometimes buried under shrubs or bushes and recovered the following day. Brown hyenas are also known to be coprophagic, which is thought to reduce water loss in arid land species. (Attenborough, et al., 2002; Maude, 2005; Nowak, 2005; Owens and Owens, 1978; Skinner and van Aarde, 1991; Wiesel, 2008)

Predation

African lions are the only major predator of adult brown hyenas. Spotted hyenas can also kill adult brown hyenas, but encounters between the two species rarely occurs due to their differing habitat preferences. Brown hyena cubs are susceptible to predation from lions, black-backed jackals and occasionally African wild dogs. Group living likely reduces predation of brown hyena cubs by these animals. When a predator approaches the den, the smallest cubs, usually those under 4 months in age, retreat underground while older cubs stand just outside the entrance with their hair erected. (Mills, 1982c; Owens and Owens, 1978; Owens and Owens, 1979)

Adult brown hyenas are most at danger when approaching a lion kill, and they sometimes delay feeding for up to 30 minutes after the lions have left to ensure their safety. They also use raised hackles and a loud, high-pitched cry to alert others of approaching lions. (Owens and Owens, 1978; Owens and Owens, 1979)

Ecosystem Roles

As a scavenger, Hyaena brunnea plays an important role in eliminating the remains of old carcasses from its environment. These carcasses are used as breeding grounds for many parasites and diseases if they are left to decay on their own. Brown hyenas are host to a number of endo- and ectoparasites, including fleas, tapeworms, nematodes, nymphs, mites and flies from the family Hippoboscidae. (Mills, 1982c)

Brown hyenas help regulate populations of black-backed jackals and South African fur seals through predation. They also alter predation frequencies of cheetahs and leopards by stalking them during hunts and then driving them off of their kills. Brown hyenas also disperse the seeds of tsama melons (Citrullus vulgaris), hookeri melons (Cucumis hookeri) and gemsbok melons (Citrullus naudinianus) at defecation sites. (Owens and Owens, 1978)

Economic Importance for Humans: Positive

Some pastoralists in southern Africa feel that brown hyenas are beneficial as a target for ecotourism, which brings money and jobs into the region. Brown hyenas also benefit humans by controlling parasite populations that rely on animal carcasses to feed and reproduce. By reducing the number of carcasses, brown hyenas help decrease chances of parasitic infestation to humans, livestock and domestic pets. (Maude, 2005)

Economic Importance for Humans: Negative

Hyaena brunnea is viewed as a livestock killer and crop pest by melon farmers. In many cases this is a misconception, with the true killers being African lions, black-backed jackals and spotted hyenas. It has been estimated that over the course of a year at a single cattle post, brown hyenas are responsible for $94 worth of damage to livestock, out of an annual total of $744 worth of damage caused by all predators. On average, it is estimated that brown hyenas kill 1.8 domestic animals per ranch annually. Many farmers set indiscriminate traps and shoot brown hyenas in an attempt to keep their livestock and crops safe. (Maude, 2005)

Negative Impacts

crop pest

Conservation Status

Brown hyenas are considered near threatened with a decreasing trend by the IUCN Red List of Threatened Species, and the U.S. Fish and Wildlife Service has listed them as endangered since 1970. It is difficult to make accurate population estimates of brown hyenas due to their nocturnal lifestyle and low population density. Low population numbers are probably due to sparse resources in the Kalahari and Namib Deserts, as well as persecution from livestock farmers in the area. The establishment of national parks and game reserves in Namibia and Botswana offer the best hope for preserving brown hyena populations. (Mills, 1982a; Nowak, 2005; Skinner and van Aarde, 1991)

Other Comments

Fossil records suggest that Hyaena brunnea has existed in Africa since the late Pliocene. This species was formerly known as Hyaena brunnea, and therefore it is found under this name in some literature. (Mills, 1982a; Nowak, 2005)

Contributors

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

biodegradation

helps break down and decompose dead plants and/or animals

carnivore

an animal that mainly eats meat

carrion

flesh of dead animals.

chemical

uses smells or other chemicals to communicate

cooperative breeder

helpers provide assistance in raising young that are not their own

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

nomadic

generally wanders from place to place, usually within a well-defined range.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polygynous

having more than one female as a mate at one time

scavenger

an animal that mainly eats dead animals

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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This material is based upon work supported by the
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Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.